The present invention relates generally to the field of scaffolding, and more particularly to an apparatus which is used to removably interconnect various components of a modular scaffolding system.
Scaffolding is used extensively in industry to provide temporary access to raised portions of a structure, such as a building or vessel under construction. A typical scaffolding system is comprised of a plurality of modular components which can be erected in a variety of configurations and dismantled for storage or transport. The basic components used in a scaffolding system are vertically oriented upright members and horizontally oriented spacers, which extend between the upright members. Diagonal spacer members may also be joined at either end to the uprights in order to maintain the rigidity of the scaffolding system. Generally, the spacers and uprights are elongate and tubular in construction. To form a horizontal surface on which workers can stand, a flat plank is placed across the horizontal spacers.
Various devices have been developed to removably interconnect the vertical uprights to the horizontal or diagonal spacers. Typically, the ends of the spacers include a tapered wedge which is slidably secured to the spacer in a manner to permit vertical motion of the wedge. To secure the spacer to the upright, the wedge is driven through a vertically oriented aperture in the upright, and is retained in place by frictional engagement with the aperture.
While these connectors have been satisfactory in terms of preventing the spacer and uprights from being pulled apart in a direction parallel to the longitudinal axis of the spacer, they have not been able to eliminate instability or wobbling of the scaffolding due to rotation of the spacer about the upright in either a horizontal or vertical plane. Another disadvantage of previous devices is that even though the spacer can be manipulated by a single worker, two workers are generally required to properly align each spacer with the uprights, thus increasing the time and labor required to erect the scaffolding. This is because the worker who is supporting and orienting the spacer usually grips the spacer proximate its mid-point, due to its length. As a result, that worker cannot get close enough to the wedge to visually inspect whether it is aligned with the aperture. Further, a second worker is often required to manually hold the wedge in a raised position, clear of the aperture, until alignment is achieved.
The vertical uprights are generally comprised of a plurality of tubular segments which are stacked end to end to reach a desired height. In order to secure adjacent segments, previous systems used a cylindrical fitting which had an outside diameter approximately equal to the inside diameter of the tubular upright segments. Each segment has an open or female end, and a male end at which the fitting is secured so as to protrude outwardly. Upon insertion of the male end or one segment into the female end of an adjacent segment, the contact between the fitting and the interior of the adjacent segment maintains the interconnected segments in a coaxial, vertical orientation.
A drawback to the cylindrical fittings is that in order to prevent relative motion between adjacent segments, a tight frictional fit must be maintained between the fitting and the inside diameter of the adjacent segment. Unfortunately, this interference between the fitting and the segment makes disassembly of the connected segments extremely difficult.
Thus, a need exists for a scaffolding connector which (1) removably secures a horizontal or diagonal spacer to a vertical upright without allowing relative motion between the spacer and upright; and (2) is easily aligned by a single worker. Additionally, a need exists for a fitting which securely interconnects adjacent upright segments yet easily allows dismantling of the interconnected segments.